1. Field of the Invention
The present invention relates to a semiconductor integrated circuit formed on a glass substrate or a flexible substrate, a semiconductor device including the semiconductor integrated circuit, and a manufacturing method of the semiconductor integrated circuit.
2. Description of the Related Art
In recent years, there has been a great need for an IC card or an IC tag capable of contactless data communication in all fields that require automatic identification, such as securities and goods management. Such an IC card or an IC tag is required to be small for increased impact resistance, inexpensive for disposable application, an affinity for paper in view of the management of securities in particular, and a large capacity memory in accordance with the increased amount of data. Thus, the development of an IC chip on a silicon substrate has been advanced by using various technologies to meet such requirements.
It is also suggested that a minute IC chip is mounted on securities to prevent abuse thereof and to allow to be reused when they are returned to the owner (see Patent Document 1: Japanese Patent Laid-Open No. 2001-260580).
A chip formed on a silicon substrate has low impact resistance since the substrate has a single crystalline structure. In addition, since a chip formed on a silicon substrate is thick, irregularity occurs on the surface of products and goods, in particular when the chip is mounted on papers such as bills or on labels attached to the products and goods. As a result, the design of the products and goods becomes less attractive.
Further, a rewritable nonvolatile memory is not easily formed on a glass substrate because of the restriction on the process temperature and the like. Accordingly, it is practical to use a nonvolatile ROM such as a mask ROM data content of which is determined during the manufacturing step and cannot be rewritten. However, stored data is necessarily different in each chip, thus in the case of a mask ROM being used, a photomask used in the step for determining data content is thrown away after use, leading to the increase in the cost of the chip. Since the unit price of such a chip is extremely low, increased cost prohibits the spread thereof.